The overall objectives of the project are to study the chemical and rheological properties of respiratory mucus and to correlate these properties with mucociliary transport. Tracheal mucus obtained via the canine pouch model is used and transport is assayed using the frog palate model. During the past year, this palate transport model has been perfected and calibrated. Results showed that mucociliary transport correlates with mucus viscoelasticity. For the coming year, we will continue studying the relationship between mucus rheology and transport on samples derived from dogs treated with various drugs as well as extend chemical and other biophysical studies intended to elucidate the relationship between mucus structure and rheological properties. BIBLIOGRAPHIC REFERENCES: "General Discussion Session on Function and Rheology of Epithelial Mucus," Second International Congress of Biorheology, Rehovot, Israel, Dec 1974/Jan 1975, Biorheology 13, 67-69 (1976). "Effect of Chronic Sulfur Dioxide Inhalation on Rheological Properties of Tracheal Mucus," Biorheology 13, 107-114 (1976).